Eight-parameter PC-AT based flow cytometric data system

An 8-parameter flow cytometric data system is described using an IBM-AT compatible personal computer (PC) and a commercial analog to digital conversion (ADC) board. A dedicated pulse processing interface adapts the flow cytometric pulses to the ADC board and controls the number of parameters to be taken up and the trigger conditions. The trigger thresholds are automatically held at a level immediately above the noise level. For the timing of kinetic measurements a linear voltage ramp of adjustable rise time is available. A built-in precision voltage source can be used for an overall calibration. The data system is operated by software written in assembly language. Data may be collected and processed in 1-8-parameter listmode or 1-3-parameter histogram mode. Functions are available for graphical color displays, numerical integration, multiparameter gating, and printing.